The present invention relates to a method for forming bundles in a bundle former that comprises a holding space in which at least one layer, composed of at least one printed product, of a bundle is deposited on a lift and is then compressed. With a method of this type, printed products made available in an overlapping flow, for example newspapers, magazines, brochures and the like, can be converted to a bundle during the further print processing operation. For an optimum bundle quality, the layers of printed products in a bundle are respectively compressed or compacted with the aid of the lift and a counter-pressure device, for example a pressing plate, before they leave the bundle former for the further processing locations. A bundle of this type comprises at least one layer which is generally composed of several individual printed products. Also known is a process of stacking the individual layers in a stacker, for example a compensating stacker, that is to say, in such a way that the backs of the printed products of successive layers are arranged opposite each other.
A method of this type is disclosed in European Patent document EP-A-1 593 633. With this method, the layers to be compressed are formed with the aid of a stacking device which is arranged above the holding space of a pressing device and which takes over the printed products from an overlapping flow. The layers are respectively dropped onto the lift of the pressing device which is then raised toward press flaps for the compressing of the layer. To accommodate an additional layer, the lift is lowered and is subsequently raised once more for the compressing. Finally, the formed bundle is lowered completely and is ejected.
European patent document EP-A-1 826 164 discloses a bundler former equipped with pivoting pressure levers which are placed from above against the formed stack. For the pressing operation, the distance between a bottom of the holding space and the pressure levers is reduced.
European patent document EP-A-0 309 745 discloses an apparatus for which the printed products are deposited with the aid of a pivoting feeder onto a stacking table. The stacking table is lowered corresponding to the pivoting angle of the feeder until a partial stack is formed.
With the aforementioned method, bundles must generally be formed at an extremely high output, wherein the printed products supplied to the bundle former are to be stacked to form an optimum bundle and are transferred out for the further processing during the shortest possible time interval. The respective cycle time should therefore be as short as possible. At the same time, a constant high bundle quality should also be ensured.